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Salvage Cryosurgery in Prostate Cancer
If the PSA level rises above the nadir level or the patient is deemed to have history of transurethral resection of the prostate (TURP) is a relative
failed clinically based on any currently employed evaluation tool (ASTRO, contraindication for salvage cryosurgery, especially if there is a large TURP
Phoenix, PSA doubling time/velocity), a prostate biopsy should be defect present, as these patients are at increased risk for urethral necrosis,
performed if there are no contraindications to further therapeutic leading to sloughing and urinary retention. The same is true for the patient
intervention. The Partin table for predicting pathological stage does not who has a history of a prior open prostatectomy for benign disease.
apply to post-radiation therapy patients. The patient with a PSA of 10ng/ml
following radiation should not be considered to have the same pathology Patient Selection Summary
as a non-radiated patient with a PSA of 10ng/ml. According to Spiess et al., Currently, there are no clearly defined guidelines to aid in the proper
a PSA level >10ng/ml at the time of diagnosis of local recurrence and a PSA selection of patients for salvage cryosurgery. The optimal candidates for
doubling time ≤16 months will predict a poor prognosis for salvage the procedure are men who have pathological evidence of locally
cryosurgery.
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If PSA doubling time is ≤6 months, there is a significantly recurrent disease without clinical evidence of metastatic disease, a PSA
higher risk for metastasis even if local disease is confirmed by biopsy.
20
≤4ng/ml,
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a PSA doubling time somewhere greater than 12–16 months,
no evidence of SV invasion, and a life expectancy >10 years.
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Prostate Biopsy
When a biopsy is performed, multiple cores should be obtained and the Technical Considerations and Modifications
pathologists should be informed that the patient has had previous Salvage cryosurgery can be performed in the patient with recurrent disease
radiation therapy, since there are definite pathological changes that can following external-beam radiotherapy as well as interstitial prostate
occur post-radiation. Benign glands affected by radiation can mimic brachytherapy, although the latter are clearly more difficult due to the
cancerous glands, and special staining with high-molecular-weight keratin interference with the previously placed seeds. Previously placed radioactive
may be necessary to make a correct diagnosis.
21
Radiation therapy may not seeds can be visualized quite well under TRUS and may cause some
eradicate cancer immediately, i.e. malignant glands may remain as they confusion as their sonographic appearance is similar to the tip
slowly undergo apoptosis. Such severely affected cancer cells may remain of the cryoneedles, especially in the transverse view. Placing the needles in
in the prostate for as long as 36 months after radiation therapy. Therefore, the sagittal plane can overcome this difficulty, since the length of the
a positive biopsy prior to 36 months after radiation treatment can be cryoneedles can be easily followed in this view. Due to the previous
extremely difficult to interpret. Consequently, an experienced reading of radiation, the gland may be adherent to the anterior rectal wall, diminishing
the post-radiation biopsy specimen is essential. As with biopsies in the the thickness of Denonvilliers’ fascia. This needs to be assessed by TRUS
non-radiated patient, there are no definite guidelines specifying prior to freezing so the surgeon can determine how to appropriately place
the number of cores that should be obtained. Recent literature has the posterior cryoprobes and the Denonvilliers’ thermocouple. If the space
indicated that extended biopsy strategies enhance the detection of cancer between the anterior rectal wall and posterior prostatic capsule is less than
and that sextant biopsies are no longer considered adequate.
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5mm, it may not be possible to drive the temperatures down to -40°C
In addition to the prostate biopsy, a biopsy of both seminal vesicles
(SV) is recommended in this setting of potential radiation failure.
Double freeze–thaw cycles have
Cancer-invaded seminal vesicles may appear normal on imaging after
significantly better outcomes in terms
radiation therapy. The incidence of SV involvement in the patient with a
rising PSA level after radiation with locally recurrent disease is much higher
of biochemical failure-free and local
than in the non-radiated patient. Pathological results from salvage radical
recurrence-free survival rates compared
prostatectomy series reveal that the rate of SV involvement can be as high
as 42%.
23
Those patients with SV invasion will have a poorer prognosis in
with one freeze–thaw cycle.
general despite successful local treatment of the prostate gland. In the
presence of SV involvement, prostate salvage cryosurgery as monotherapy
is not likely to be successful, and the use of hormonal/chemotherapy safely, and freezing should be terminated when the leading edge of the ice
approaches in these patients is likely to improve outcomes. ball has extended just beyond the capsule, even if the target temperature of
-40°C is not reached. Double freeze–thaw cycles have significantly better
Metastatic Work-up outcomes in terms of biochemical failure-free and local recurrence-free
If a prostate biopsy reveals recurrent cancer in the gland, a metastatic survival rates compared with one freeze–thaw cycle.
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evaluation including nodal imaging of the abdomen and pelvis as well as a
bone scan should be performed. Open or laparoscopic biopsy of When counseling patients for any salvage procedure, the risks of urinary
the pelvic lymph nodes may also be considered for high-risk patients. The incontinence need to be addressed. The placement of a thermosensor to
lymph node positivity rate in patients from the salvage radical monitor the temperature of the external sphincter can reduce the
prostatectomy series ranges from 11 to 40%. The role of the capromab potential of thermal injury to this muscle. The thermosensor is introduced
pendetide scan in patients undergoing salvage cryosurgery has not been through the perineal skin and advanced until the impression of the tip of
extensively studied, but may play a role in the patient with high-volume the thermocouple can be seen in the sphincter. The placement can be
disease or where the PSA doubling time is less than six months. Prostate documented by TRUS or cystoscopy. There is no documented evidence of
size is less of a problem when considering salvage cryosurgery as the benefit from hormone therapy prior to salvage cryosurgery except for
prostate of radiated patients loses volume after radiation therapy. A prior down-sizing purposes.
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